Metal clad switchgear for high voltage comprising compartments adapted to be divided by movable transverse partition walls

ABSTRACT

In metal clad switchgear the provision of slide valves to divide compartments in two parts which are separated from one another in a gastight manner, when said slide valves are in their closed position, said slide valves being held against movement in a direction at right angles to their plane by guides and cooperating with axially movable, coaxial sealing rings which are supported by the envelope of said compartments and forced against said slide valves by springs.

7 United States Patent [72] Inventor Egbertus Adrlanus Froweln Arnhem,Netherlands [2 1] Appl. No. 76,749

[22] Filed Sept. 30, I970 [45] Patented Dec. 21, 1971 [73] Assignee N.V.COQ,

Utrecht, Netherlands [54] METAL CLAD SWITCI'IGEAR FOR HIGH VOLTAGECOMPRISING COMPARTMENTS ADAPTEI) TO BE DIVIDED BY MOVABLE TRANSVERSEPARTITION WALLS 5 Claims, 4 Drawing Figs.

[52] U.S.CI 317/103, 200/148 B [5 I Int. Cl H0111 33/82 [50] Field ofSearch 200/148 B,

[56] References Cited UNITED STATES PATENTS 3,367,625 2/1968 Fortune251/328 X 3,564,344 2/1971 Boersma 317/103 FOREIGN PATENTS 6,71 1,5742/1969 Netherlands 200/148 R Primary Examiner-Lewis 1-1. Myers AssistantExaminer-Gerald P. Tolin Attorney-Snyder & Butrum II 3 a 4, 1 1 a 203 mI 233 lTiTI 1 ill i J82 J l J 1 k 1 3% $32 55 i2 23 T v 5 2 2b \i 3b ViPATENTED 05221 I971 3629166 1v SHEET 1 BF 2 ZNVENTOR PATENTED M021 IQTISHEET 2 OF 2 IN VENTOR METAL CLAD SWITCI'IGEAR FOR HIGH VOLTAGECOMPRISING COMPARTMEN'IS ADAPTED TO BE DIVIDED BY MOVABLE TRANSVERSEPARTITION WALLS The invention relates to metal-clad switchgear for highvoltage comprising a gas-filled metal envelope, which is intended to beconnected with earth and divided into a number of compartments, of whichat least one compartment is divided into two parts interconnected by achamber containing a transverse partition wall which is adapted to bemoved in its plane and to separate said compartment parts from oneanother and from said chamber in an airtight manner.

Metal clad switchgear of this kind is disclosed in the Dutch Pat.application Nos. 295,463 and 67.11574 laid open for public inspection.In this switchgear the transverse partition walls are provided incompartments used for isolator-switches and each partition wall consistsof two coaxial discs adapted to be moved in their planes together andaxially in respect of each other and to be forced, in their closedposition, as a valve against a seat formed on the envelope. Such acomposite transverse partition wall can not be easily made resistant topressure, so that at the occurrence of a considerable increase ofpressure or an explosion in one of the parts of the isolatorswitchcompartment the risk is great, that the relative disc is forced from itsseat, the driving mechanism of the discs is wrenched out of position andleakage occurs.

The invention has for its object to provide a transverse partition wallfor such switchgear which has a simpler construction, resists explosionsbetter and gives a better seal when the pressure in the parts of thecompartment separated by the partition wall increases. This is achievedin that the partition wall consists of one single plate-shaped slidevalve kept in its path by guides and adapted to be positioned into twoend positions and said slide valve has an uninterrupted portion whichseparates, in one end position of the slide valve, the parts of saidcompartment from one another and a portion with a hole whichinterconnects, in the other end position of the slide valve, the partsof said compartment, whereas on each one of the two sides of the slidevalve an axially movable sealing ring supported by the envelope of thecompartment is provided, said ring being forced, at least in the closedcondition of the slide valve, against said valve by springs and formingon its outer circumference with said envelope as well as on its endsurface facing the slide valve with said valve gas-tight seals. Incontrast with the known discs this valve is held against axial movementby its guides. The sealing rings can not be lifted from the valve at anincrease of pressure, so that also at the event of an explosion areliable seal is ensured. Moreover, if at least between the end face ofeach sealing ring facing the slide valve and the slide valve, when it isin its closed end position, a packing ring is provided, of which theinner diameter is smaller than the outer diameter of the relativesealing ring said ring will be pressed against the valve with increasingforce, when the pressure in the part of the compartment closed by thevalve and said ring increases, so that the seal adapts itself to theprevailing pressure difference and is thus maintained.

In order to facilitate the movement of the valve a construction isrecommended, in which each sealing ring is provided with rollers mountedfor rotation about axes which are parallel to the plane of the slidevalve and are directed transversely to the direction of movementthereof, said rollers rolling during the movement of the slide valve onthe surface of the slide valve which faces the relative sealing ring andholding said ring free from the slide valve, and the slide valve, isprovided with recesses in the surface facing said sealing ring, saidrollers engaging, at least in the closed end position of the slidevalve, said recesses, in such a manner, that said ring is forced againstthe slide valve by its springs. In order to prevent that during themovement of the slide valve the rollers of the sealing ring enterrecesses of the valve which are not intended for them, it isadvantageous to place the rollers of each sealing ring in such a mannerthat each one of them follows, during the movement of the slide valve,an individual path on the slide valve which is free from the recesses ofsaid valve intended for the other rollers.

It appears from the Dutch Pat. application No. 67.11574 laid open topublic inspection that in each compartment adapted to be divided by atransverse partition wall and containing a switch, of which the fixedcontact is found on one side and the axially movable switching rodcooperating with said fixed contact is found, when it is in itsswitched-off position, on the other side of said partition wall, saidswitching rod extending through a bushing insulator which is mountedbetween said compartment and an adjacent compartment separated therefromand, when it is in its switched-off position, extending partly in onepartly in the other compartment, means may be provided which establishin the switched-off position of said switching rod a connection betweenthe two compartments. In said known switchgear said means consist of aconnecting conduit or passage comprising a valve controlled by themovable transverse partition wall. However, as the transverse partitionwall can only be positioned in its closed position, when the switch isswitched-off, said connection between the two compartments can beobtained in a simpler and less vulnerable way, when said switching rodis provided with a passage which interconnects the two compartmentsexclusively when said rod is in its switched-off position. In that casethe switching rod operates at the same time as a valve for the purposereferred to.

The invention will be further elucidated with the aid of the drawing. Inthe drawing:

FIG. 1 is a diagrammatical view of a part of metal-clad switchgearaccording to the invention,

FIG. 2 is a longitudinal sectional view of a valve mechanism andaccessories used in the switchgear shown in FIG. 1,

FIG. 3 is a cross-sectional view taken on line III-III in FIG. 1 andFIG. 4 is, on a smaller scale, a plan view of the valve body and asealing ring of the valve mechanism shown in FIGS. 2 and 3 and seen inthe plane IV-IV shown in FIG. 3.

In FIG. 1 the shown part of the switchgear consists of compartments 2,3, 4 separated from each other by bushing insulators 5, 6 and surroundedby an envelope 1 which has to be connected with earth. The compartment 3can be divided by a transverse partition wall 7 adapted to be moved inits plane into two parts 30, 3b which are separated from one another ina gas-tight manner. These parts 3a, 3b of the compartment 3 areinterconnected by a chamber 8, in which the partition wall 7 is mountedfor movement. The compartment 2 contains switches and accessories whichare not further described. Accommodated in the compartment 3 is anisolator-switch, of which the fixed contact 9 is found in the part 3bbelow the partition wall 7 and the switched-off switching rod 10 isfound in the part 3a above the partition wall 7. The compartment 4contains a busbar 11 of a busbar-system.

It appears from FIGS. 2, 3 and 4 that the transverse partition wall 7can be constructed as a single plate-shaped slide valve, of which oneportion 7a is uninterrupted and an other portion 7b lying in thedirection of movement next to said portion 7a has a hole 12. If theslide valve 7 is positioned with its uninterrupted portion 7a in thecompartment 3 (FIG. 2) the parts 3a and 3b of said compartment areseparated from each other. If the slide valve 7 is positioned with itsportion 7b provided with the hole 12 in said compartment the parts 30and 3b thereof are in open communication with one another and theisolator-switch 9, 10 can be switched in and off.

The valve 7 is provided on its longitudinal sides with guiding ribs 13which slidingly engage grooves 14 formed in strips 15 of a frame formingpart of the envelope of the chamber 8. This frame may be directlyattached to the base of the switchgear. The valve 7 is thus held againstmovement in a direction perpendicular to its plane.

Provided in the annular portions 16a, 16b of the envelope 1 whichsurrounds the parts 3a and 3b of the isolator-switch compartment 3 arecoaxial, axially movable sealing rings 17a, 17b which each supportpressure members 18a, 18b and are each forced against the valve 7 bysprings 19a, 19b lying against said pressure members. Each one of thesealing rings 17a, 17b is provided on its circumference with a packingring 20a, 20b which forms a gas-tight seal between the sealing ring andthe envelope portion 16a, 16b. In its uninterrupted portion 7a the slidevalve is provided with a packing ring 21a, 21b, against which thesealing ring 17a, 17b is forced. The inner diameter of the packing ring21a, 21b is smaller than the outer diameter of the sealing ring 17a,17b, so that, when for instance a higher gas pressure prevails in theportion 3a of the isolator-switch compartment 3 than in the part 3b ofsaid compartment and in the chamber 8, the sealing ring 70 is alsoforced against the slide valve 7 by the difference in gas pressure. Thatis why under all circumstances, consequently also at the event of anexplosion, a reliable seal is ensured between the parts 3a and 3b of thecompartment 3, when the slide valve is closed.

In order to facilitate the sliding movement of the slide valve 7 eachsealing ring 17a, 17b is provided with rollers 22a, 23a, 24a, 25a and22b, 23b, 24b, 25b mounted for rotation about axes which are parallel tothe plane of the slide valve and are directed transversely to thedirection of movement thereof. If these rollers roll on the sides of theslide valve they keep the sealing rings 17a and 17b lifted from theslide valve. However, the slide valve is locally provided in its portion7a with recesses 26a, 27a, 28a, 29a and 26b, 27b, 28b, 29b which are soarranged that, when the slide valve 7 is in its closed end position, therollers 22-25 engage the recesses 26-29 and the sealing rings 17a and17b are forced against the sliding valve by their springs 19a, 1%. It isobserved, that in the illustrated embodiment such recesses are alsopresent in the portion 7b of the slide valve, so that the sealing rings17a and 17b are also forced against the slide valve, when the latter isin its open position. However, this is not always necessary. Due theretocontaminating products produced by the switching operation can not enterthe chamber 8 and the guides l3, 14 of the slide valve 7.

The rollers 22-25 are so positioned, that each one of them follows itsown path on the valve 7. Owing thereto it is prevented that, during themovement of the slide valve, a roller enters a recess 26-29 of the slidevalve which is not intended for said roller.

If the valve 7 is closed, it is possible that the volume of each part30, 3b of the isolator-switch compartment 3 becomes dangerously small,what may result in a too rapid increase of pressure in such a part atthe occurrence of a short circuit to earth. That is why the part 3b ofsaid compartment is permanently connected with the compartment 4 bymeans of openings 30 made in the insulator 6 (FIG. I), whereas providedin the switching rod is a passage 31 which forms, exclusively in theswitched-off position of the switching rod [0, a connection between thepart 3a of the compartment 3 and the compartment 2. The switching rod 10thus operates also as a valve in a connecting conduit provided betweenthe compartments 2 and 3.

What we claim is:

1. Metal-clad switchgear for high voltage comprising a gasfilled metalenvelope intended to be connected with earth, a

number of compartments formed in said envelope, a chamberinterconnecting two parts of one of said compartments, a plate-shapedslide valve accommodated in said chamber and adapted to form therein atransverse partition wall, said slide valve being mounted for movementin its plane and adapted to separate said compartment parts from oneanother and from said chamber in a gas-tight manner, guides for holdingsaid slide valve in its path, one portion of the slide valve beinguninterrupted and separating the two parts of said compartment, when theslide valve is in its one end position, a hole formed in another portionof the slide valve and interconnecting the two parts of saidcompartment, when the slide valve is in its other end position, twosealing rings being axially movably supported by said envelope, each oneof said sealing rings bein provided on an individual side of the slidevalve, springs to orce said sealing rings towards said slide valve, and

gas-tight seals being formed, at least when the slide valve is in itsclosed end position, both between the outer circumferences of saidsealing rings and the envelope and between the one end faces of saidsealing rings and said slide valve.

2. Metal-clad switchgear as claimed in claim 1, comprising in additionpacking rings which are confined, when the slide valve is in its closedend position, between the one end faces of the sealing rings and theslide valve, the inner diameter of said packing rings being smaller thanthe outer diameter of said sealing rings.

3. Metal-clad switchgear as claimed in claim 1, comprising in additionsets of rollers mounted for rotation on the sealing rings about axeswhich are parallel to the plane of the slide valve and directedtransversely to the direction of movement thereof, said rollers rollingduring movement of the slide valve on the surfaces thereof and holdingsaid sealing rings free from the slide valve, and recesses formed in thesurfaces of the slide valve, each roller engaging, at least when theslide valve is in its closed end position, such a recess so as to allowthe sealing rings to be forced against the slide valve by their springs.

4. Metal-clad switchgear as claimed in claim 3, in which the rollers ofeach sealing ring are so arranged as to follow, during the movement ofthe slide valve, their own paths on said valve, the path of each rollerbeing free from the recesses formed in the slide valve and cooperatingwith the other rollers.

5. Metal-clad switchgear as claimed in claim 1, comprising in addition afixed contact, an axially movable switching rod cooperating therewith,said fixed contact and said switching rod constituting together aswitch, said switch being accommodated in the compartment provided withthe slide valve, said fixed contact being arranged in the part of saidcompartment on one side and said switching rod being situated, when itis in its switched-off position, partly in the part of said compartmenton the other side of the chamber containing the slide valve, a secondcompartment adjacent to said first mentioned compartment, a bushinginsulator provided in the wall between the two compartments, saidswitching rod extending through said bushing insulator and being found,when it is in its switched-off position, in both compartments and apassage formed in said switching rod, said passage interconnecting saidtwo compartments only when the switching rod is in its switched-offposition.

8 i t t 1

1. Metal-clad switchgear for high voltage comprising a gasfilled metalenvelope intended to be connected with earth, a number of compartmentsformed in said envelope, a chamber interconnecting two parts of one ofsaid compartments, a plateshaped slide valve accommodated in saidchamber and adapted to form therein a transverse partition wall, saidslide valve being mounted for movement in its plane and adapted toseparate said compartment parts from one another and from said chamberin a gas-tight manner, guides for holding said slide valve in its path,one portion of the slide valve being uninterrupted and separating thetwo parts of said compartment, when the slide valve is in its one endposition, a hole formed in another portion of the slide valve andinterconnecting the two parts of said compartment, when the slide valveis in its other end position, two sealing rings being axially movablysupported by said envelope, each one of said sealing rings beingprovided on an individual side of the slide valve, springs to force saidsealing rings towards said slide valve, and gas-tight seals beingformed, at least when the slide valve is in its closed end position,both between the outer circumferences of said sealing rings and theenvelope and between the one end faces of said sealing rings and saidslide valve.
 2. Metal-clad switchgear as claimed in claim 1, comprisingin addition packing rings which are confined, when the slide valve is inits closed end position, between the one end faces of the sealing ringsand the slide valve, the inner diameter of said packing rings beingsmaller than the outer diameter of said sealing rings.
 3. Metal-cladswitchgear as claimed in claim 1, comprising in addition sets of rollersmounted for rotation on the sealing rings about axes which are parallelto the plane of the slide valve and directed transversely to thedirection of movement thereof, said rollers rolling during movement ofthe slide valve on the surfaces thereof and holding said sealing ringsfree from the slide valve, and recesses formed in the surfaces of theslide valve, each roller engaging, at least when the slide valve is inits closed end position, such a recess so as to allow the sealing ringsto be forced against the slide valve by their springs.
 4. Metal-cladswitchgear as claimed in claim 3, in which the rollers of each sealingring are so arranged as to follow, during the movement of the slidevalve, their own paths on said valve, the path of each roller being freefrom the recesses formed in the slide valve and cooperating with theother rollers.
 5. Metal-clad switchgear as claimed in claim 1,comprising in addition a fixed contact, an axially movable switching rodcooperating therewith, said fixed contact and said switching rodconstituting together A switch, said switch being accommodated in thecompartment provided with the slide valve, said fixed contact beingarranged in the part of said compartment on one side and said switchingrod being situated, when it is in its switched-off position, partly inthe part of said compartment on the other side of the chamber containingthe slide valve, a second compartment adjacent to said first mentionedcompartment, a bushing insulator provided in the wall between the twocompartments, said switching rod extending through said bushinginsulator and being found, when it is in its switched-off position, inboth compartments and a passage formed in said switching rod, saidpassage interconnecting said two compartments only when the switchingrod is in its switched-off position.